When event is created based on planned work shift default project for this event is the one shift was planned. In project management settings you can configurate if event is targeted to a work shift's location or to person's default project.
Configuration can be done in the service in project management settings (Worktime - Administration - Working community settings OR Setting groups - Projects).
If setting is set to 'No' Nepton uses default project set in person's information page in Employees.